Molecular phylogeny of the genera Palaemon and Palaemonetes (Decapoda, Caridea, Palaemonidae) from a European perspective

A molecular phylogenetic study by Murphy & Austin (2003) showed that Australian representatives of three shrimp genera of the family Palaemonidae (Palaemon, Palaemonetes, and Macrobrachium) do not cluster according to their generic classification. According to their results, the monophyly of these genera is questioned and the generic classification of the subfamily Palaemoninae is at stake. A large number of representatives of Palaemon and Palaemonetes inhabit European waters, including the type species of each genus. To clarify the phylogeny of these species, and thus the position of the generic names Palaemon and Palaemonetes on a phylogenetic tree, we obtained DNA sequences of the same genetic markers (16S mtDNA) as used by Murphy & Austin (2003) and re-addressed the question of taxonomy and phylogeny of these two genera within the subfamily Palaemoninae. Our results confirm the paraphyly of Palaemon and Palaemonetes. In contrast, the resulting monophyletic clades reflect the geographic distribution of the species according to their respective continents: Africa-Europe, Asia, Australia, and America. With the exception of Palaemon elegans the Afro-European species cluster in a way that would support monophyly of the two genera, if representatives from other continents are excluded. Possible taxonomic solutions are discussed.